A Novel Deep Junction Edge Termination for Superjunction MOSFETs

In this letter, a novel edge termination named deep junction termination for silicon superjunction (SJ) MOSFETs is proposed, simulated, and experimentally demonstrated for the first time. By utilizing a typical implantation-and-epitaxy process to form Pand N-pillars for SJ, it is possible to form deep junctions as the device termination with a large radius of curvature and lateral and vertical doping gradation. The 2-D simulation shows that more than 700-V blocking voltage (BV) can be achieved by a 57-μm drift layer with this novel termination, and experimentally BV as high as 660 V is demonstrated by the fabricated device.